Dynamic handover parameter adjustment based on amount of packet drops at dual-connectivity access node pair

ABSTRACT

A system may include an access node to deploy a radio air interface to provide wireless services to one or more wireless devices. The access node may include processing circuitry. The processing circuitry of the access node may monitor an amount of packet drops at a shared network device of a dual connectivity access-node-pair. The processing circuitry of the access node may dynamically adjust one or more handover parameters based on the amount of packet drops at the shared network device. The handover paramters may be adjusted to inhibit handovers to the dual connectivity access-node-pair.

TECHNICAL BACKGROUND

A wireless network, such as a cellular network, may include one or moreaccess nodes (e.g., base stations) to wirelessly communicate with one ormore wireless devices (also known as user equipment (UE)), for examplevia radio frequency transmissions. An access node may provide one ormore cells that the wireless devices may connect to for wirelesscommunication, with each cell corresponding to a frequency band and aradio access technology (RAT) and having a corresponding coverage area(sector). Some wireless networks may utilize multiple frequency bandsand/or multiple RATs for wireless communication. In some networks, cellshaving different frequency bands and/or different RATs may have the sameor overlapping coverage areas.

As wireless networks evolve and grow, there are ongoing challenges incommunicating data across different types of networks. For example, aswireless technology continues to improve, various different RATs may bedeployed together within a single wireless network. Such heterogeneouswireless networks can include newer 5G and millimeter wave (mm-wave)networks, as well as older legacy networks (such as 3G). In some cases,when access nodes utilizing one RAT (e.g., 5G new radio (NR)) aredeployed alongside or co-located with access nodes utilizing another RAT(e.g., 4G long-term evolution (LTE)), dual connectivity technology maybe utilized to allow the wireless device to be simultaneously connectedto multiple cells utilizing the different RATs. One example ofdual-connectivity technology is E-UTRAN-NR Dual Connectivity (EN-DC),which enables a wireless device to be connected to a 4G LTE cell and a5G NR cell at the same time. Hereinafter, two or more access nodes thatare arranged to work together using dual-connectivity technology, sothat a wireless device may connect to all of the nodes simultaneously,may be referred to as a “dual connectivity access-node-pair,” a “pair”of nodes, “paired” nodes, or a “node-pair.” Other terms occasionallyused in the art to refer to such a dual connectivity access-node-pairinclude “dual connectivity group,” “EN-DC group,” “cell group,” and thelike. Note that “pair” as used herein is not limited to just two units,but may include two or more units; thus, a “dual connectivityaccess-node-pair” is not limited to just two nodes, but may include anynumber of nodes.

In some dual connectivity systems, control information is transmittedusing just one RAT (e.g., LTE), while user data is transmitted using theother RAT (e.g., 5G NR) or using both RATs (e.g., LTE and 5G NR). Insome examples utilizing this arrangement, the node that handles controlplane communication may be referred to as the “master” node or the“anchor” node, while the other node(s) may be referred to as a“secondary” node(s). In some cases, a wireless device may connect firstto the master node, and then the master node may establish a connectionbetween the wireless device and the secondary node if possible.

In some dual connectivity systems, data may be communicated with awireless device using both RATs simultaneously, for example usingtransmissions methods known as “concurrent mode”, or “split mode.” Insome cases, concurrent mode transmissions may be enabled by utilizing anantenna array that can simultaneously transmit (or receive) usingmultiple RATs (e.g., both 4G and 5G). For example, a cell site mayinclude two (or more) paired access nodes that share an antenna array(and possibly other equipment such as a power supply), thus enablingsimultaneous transmissions of data from the two nodes to the samewireless device via the same antenna array. As throughput andconnectivity are positively correlated with power output, the split modeantenna array can control throughput and connectivity on each protocolby allocating power between the two nodes. This sharing of equipment notonly reduces costs by avoiding the need to purchase multiple instancesof equipment for the several nodes, but may also reduce the spacerequirements for that equipment at the cell site, where space is oftenat a premium, or potentially avoid the need for using multiple cellsites.

One difficulty in heterogenous networks that utilize dual connectivityis how to determine which cells the wireless devices should connect toand under what conditions they should be handed over to different cells.Existing techniques for handling handovers may not be well suited to thecontext of dual connectivity networks, as these techniques may fail toaccount for the wireless device being simultaneously connected tomultiple access nodes utilizing different RATs, the differentcharacteristics of these RATs, and the interactions between these accessnodes. Accordingly, examples disclosed herein may include improvedtechniques for managing handovers in the context of dual connectivitynetworks.

OVERVIEW

Examples described herein include systems, methods, and processing nodesfor dynamic handover parameter adjustment in a dual-connectivity networkbased on amount of packet drops at a shared router.

In one example, a method includes monitoring an amount of packet dropsat a shared network device of a dual connectivity access-node-pair, anddynamically adjusting one or more handover parameters based on theamount of packet drops at the shared network device. The method may alsoinclude detecting whether the amount of packet drops satisfies athreshold criterion, and in response to the amount of packet dropssatisfying the threshold criterion, adjusting the one or more handoverparameters to inhibit handovers to a cell of the dual connectivityaccess-node-pair.

In another example, a system may include an access node configured todeploy a radio air interface to provide wireless services to one or morewireless devices. The access node may include processing circuitryconfigured to: monitor an amount of packet drops at a shared networkdevice of a dual connectivity access-node-pair, and dynamically adjustone or more handover parameters based on the amount of packet drops atthe shared network device.

In another example, a processing node is configured to performoperations, which may include e monitoring an amount of packet drops ata shared network device of a dual connectivity access-node-pair, anddynamically adjusting one or more handover parameters based on theamount of packet drops at the shared network device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts example wireless network.

FIG. 2A depicts an example dual-connectivity access node pair.

FIG. 2B depicts examples communication in the example dual-connectivityaccess node pair.

FIG. 3 depicts an example access node.

FIG. 4 depicts an example processing node.

FIG. 5 depicts an example method for dynamic handover parameteradjustment in a dual-connectivity network.

FIG. 6 depicts another example method for dynamic handover parameteradjustment in a dual-connectivity network.

FIG. 7 depicts another example method for dynamic handover parameteradjustment in a dual-connectivity network.

DETAILED DESCRIPTION

Example embodiments described herein include systems, methods, anddevices (e.g., processing nodes) for dynamic handover parameteradjustment based on an amount (rate) of packet drops at a shared networkdevice of a dual-connectivity access node pair. Example embodimentsdescribed herein also include software (computer readable instructions)that may be stored on machine readable media and executed to cause aprocessor to perform operations described herein. The disclosed systemsand methods may be implemented in any wireless networks in which accessnodes utilize dual-connectivity techniques. In particular, the disclosedsystems and methods may be beneficially employed, for example, inscenarios in which a pair of dual-connectivity access nodes share anetwork device (e.g., router) for inter-node and/or backhaulcommunication.

As noted above, existing techniques for managing handovers may not bewell suited to the dual-connectivity context, as they may fail toaccount for various aspects of dual-connectivity. For example, oneaspect of a dual connectivity system not well-addressed by existinghandover techniques is the inter-node communication that often occursbetween paired dual-connectivity access nodes. In some circumstancessubstantial amounts of data may need to flow between a pair ofdual-connectivity access nodes, and this inter-node communication canaffect the quality of communication with the wireless devices if itbecomes heavy enough. Moreover, paired nodes may often be deployedtogether as part of a same cell site, and may share network equipmentsuch as a cell-site router (CSR). In addition to the substantial amountsof data that would normally flow through such shared equipment, in somescenarios the aforementioned inter-node communication may also be routedthrough such shared equipment, and thus extreme traffic congestion mayoccur at times. In this arrangement, it is possible for some datapackets to be dropped at the router. If the amount of packet drops atthe router becomes too high, this can reduce the quality of experience(e.g., network throughput) for wireless devices connected to the pair ofnodes.

Existing techniques for handover management do not account for suchpacket drops at a router of a node pair of a dual-connectivity system.Under existing handover techniques, each wireless device measures thesignal strength of the wireless air interface of the various cells itcan potential connect to, and a cell is selected by considering varioushandover criteria that generally compare the signal strengths of thetarget cells and/or the currently serving cell to specified handoverparameters (e.g., threshold values). Generally, the wireless device willtry to connect to the cell that has the strongest wireless signal,assuming other criteria a met. For example, a wireless devices may stayconnected to their current cell until its signal strength become too low(as defined by the handover parameters) and/or until a cell with asignal strength sufficiently higher than that of the current servingcell (as defined by the handover parameters) is available.

But in a state in which there are high router packet drops at adual-connectivity node pair, a new wireless device connecting to a cellof the affected node pair may experience sub-par network performanceeven if the signal strength of the cells is relatively high. Moreover,the addition of more wireless devices to the affected node pair, e.g.,via handovers, may worsen the packet drops at the shared network device,due to the additional data streams associated with the new wirelessdevices. Thus, to avoid a poor quality of experience for a wirelessdevice considering connecting to the affected node-pair and to avoidexacerbating existing packet drops at the shared router, it may bepreferable for the wireless device to connect to (or remain connectedto) another access node even if the signal strength of the other accessnode is relatively weak compared to the signal strength of the affectednode-pair.

Thus, in example techniques disclosed herein the amount of packet drops(per unit time) at the shared router may be monitored, and if the amountbecomes too high then the system may take actions to inhibit thehandover of wireless devices to the affected node pair. In some cases,when handovers to a node-pair are inhibited it may still be possible fora handover to the affected node-pair to occur, for example if the signalstrengths of other candidate nodes are sufficiently poor relative to thesignal strength of the affected node-pair, but the disparity in signalstrength that is required to justify a handover may be made higher thannormal so that fewer wireless devices will qualify for a handover to theaffected node-pair. In other cases, inhibiting handovers may includepreventing handovers entirely. In either case, inhibiting handovers to acell of a node-pair experiencing high packet drops at their sharedrouter results in fewer new connections of wireless devices to theaffected node-pair, thus avoiding exacerbating the packet drops at theshared network device. In addition, wireless devices that otherwisewould have been handed over to the affected node-pair without theinhibition of handovers may have a better quality of experience thanthey would have if they had been handed over.

Inhibiting handovers to a node-pair experiencing high packet-drops maybe accomplished by, for example, dynamically adjusting one or morehandover parameters in a direction that makes a handover to the affectednode-pair less likely (i.e., by making it more difficult to satisfy oneor more handover criteria). Examples of handover parameters that may beadjusted to inhibit handovers include handover thresholds, handoveroffsets, and the like. The access nodes may also communicate informationto adjoining access nodes that enables the adjoining nodes to adjusttheir handover parameters to inhibit wireless devices in their coveragearea from being handed over to the node-pair experiencing high packetdrops at the shared router. For example, an access-node-pair may shareinformation with adjoining access nodes that quantitatively indicatesthe amount of packet-drops, such as by communicating a numberrepresenting the packet drop rate. This quantitative information enablesthe adjoining access nodes to make the primary determination forthemselves based directly on the data as to whether or not (and in somecases by how much) they should inhibit handovers to theaccess-node-pair. In other examples, the access-node-pair may make theprimary determination as to whether an amount of packet drops at theirown shared network device is high (i.e., exceeds a threshold) and/orwhether inhibiting of handovers is warranted, and then may shareinformation with adjoining access nodes that qualitatively indicates tothe adjoining access nodes that they should inhibit handovers to theaccess-node-pair. In such cases, the adjacent access nodes may rely onthe determination made by the access-node-pair that packet drops arehigh and/or that inhibiting of handovers is needed, and initiate theirown handover parameter adjustments to inhibit handovers to theaccess-node-pair based on this qualitative information, withoutnecessarily analyzing the underlying quantitative data.

The term “wireless device” refers to any wireless device included in awireless network. For example, the term “wireless device” may include arelay node, which may communicate with an access node. The term“wireless device” may also include an end-user wireless device, whichmay communicate with the access node through the relay node. The term“wireless device” may further include an end-user wireless device thatcommunicates with the access node directly without being relayed by arelay node.

FIG. 1 depicts an example system for wireless communication. System 100may be a wireless communication network, such as a cellular network.System 100 may include a radio access network (“RAN”) 160 and a core orbackend network 150. The RAN 160 may include access nodes 110 to deploya radio air interface serving one or more wireless devices 140. The corenetwork 150 may connect the RAN 160 to other networks 101, such as theInternet, and may provide services such as control plane management,subscription management, etc. In FIG. 1 , the core network 150 comprisesa gateway 102 and a controller node 104. Each wireless device 140 may beattached to the wireless air interface deployed by an access nodes 110via wireless communication links 145. Access nodes 110 may communicatewith the core network 150 via communication links, such as thecommunication links 106, 107 illustrated in FIG. 1 . Access nodes 110may communicate with each other using a communication link 108. Althoughtwo access nodes 110 are illustrated in FIG. 1 for simplicity, anynumber of access nodes 110 may be included in the system 100. System 100can include various other components besides those illustrated, andother combinations or arrangements of carriers/wireless air interfaces,antenna elements, access nodes, and wireless devices, as may be evidentto those having ordinary skill in the art in light of this disclosure.

The system 100 may use one or more wireless network protocols, such asone or more of Multimedia Broadcast Multicast Services (MBMS), codedivision multiple access (CDMA) 1xRTT (radio transmission technology),Global System for Mobile Communications (GSM), Universal MobileTelecommunications System (UMTS), High-Speed Packet Access (HSPA),Evolution Data Optimized (EV-DO), EV-DO rev. A, WorldwideInteroperability for Microwave Access (WiMAX), Third GenerationPartnership Project Long Term Evolution (3GPP LTE), Fourth Generationbroadband cellular (4G, LTE Advanced, etc.), and Fifth Generation mobilenetworks or wireless systems (5G, 5G New Radio (“5G NR”), or 5G LTE).The system 100 may be a heterogenous system configured to deploy dualconnectivity techniques. Thus, at least two of the access nodes 110 maybe part of a dual-connectivity node-pair and may utilize differentRATs-for example, one of the access nodes 110 may utilize a 4G LTE RATand another access node 110 may utilize a 5G NR RAT. The node-pair mayutilize, for example, EN-DC and/or concurrent mode techniques. Specificexamples of the dual connectivity configuration of one example node-pairwill be described in greater detail below in relation to FIG. 2 .

In the example system 100 shown in FIG. 1 , access nodes 110 may bemacro-cell access nodes configured to deploy a wireless radio airinterface including one or more cells, each cell having a correspondingfrequency band, a corresponding RAT, and a corresponding coverage areasuch as the coverage area 111 illustrated in FIG. 1 . Each access node110 may be any network node configured to provide communication betweenend-user wireless devices 140 and a communication network 101, includingstandard access nodes such as a macro-cell access node, a basetransceiver station, a radio base station, an evolved Node B (eNodeB)device, an enhanced eNodeB device, a next generation NodeB (or gNodeB)in 5G NR, or the like. Components of access nodes 110 are furtherdescribed below in relation to FIG. 3 .

Wireless devices 140 may be any device, system, combination of devices,or other such communication platform configured to wirelesslycommunicate with access node 110 using one or more frequency bandsdeployed therefrom. For example, end-user wireless devices 140 mayinclude a mobile phone, a wireless phone, a wireless modem, a personaldigital assistant (PDA), a voice over internet protocol (VoIP) phone, avoice over packet (VOP) phone, a soft phone, a computer, a tablet, awearable smart device, an internet-of-things (IoT) device, as well asother types of devices or systems that may send and receive signals ordata. Other types of communication platforms are contemplated.

Communication network 101 may be a wired and/or wireless communicationnetwork. Communication network 101 may include processing nodes,routers, gateways, and physical and/or wireless data links forcommunicating signals among various network elements. Communicationnetwork 101 may include one or more of a local area network, a wide areanetwork, and an internetwork (including the Internet). Communicationnetwork 101 may be capable of communicating signals, for example, tosupport voice, push-to-talk, broadcast video, and data communication byend-user wireless devices 140. Wired network protocols utilized bycommunication network 101 may include one or more of Ethernet, FastEthernet, Gigabit Ethernet, Local Talk (such as Carrier Sense MultipleAccess with Collision Avoidance), Token Ring, Fiber Distributed DataInterface (FDDI), and Asynchronous Transfer Mode (ATM). Communicationnetwork 101 may include additional base stations, controller nodes,telephony switches, internet routers, network gateways, computersystems, communication links, or other type of communication equipment,and combinations thereof. The wireless network provided by access node110 may support any of the above-mentioned network protocols.

Communication links 106, 107, and 108 may use various communicationmedia, such as air, laser, metal, optical fiber, or other signalpropagation path, including combinations thereof. Communication link106, 107, and 108 may be wired or wireless and may use variouscommunication protocols such as Internet, Internet protocol (IP),local-area network (LAN), optical networking, hybrid fiber coax (HFC),telephony, T1, or other communication format, including combinationsthereof. Wireless communication links may be a radio frequency,microwave, infrared, or other signal, and may use a suitablecommunication protocol, for example, Global System for Mobiletelecommunications (GSM), Code Division Multiple Access (CDMA),Worldwide Interoperability for Microwave Access (WiMAX), Long TermEvolution (LTE), 5G NR, or combinations thereof. Communication links106, 107, and 108 may be direct links or may include variousintermediate components, systems, and networks. Communication links 106,107, and 108 may enable different signals to share the same physicallink. Thus, although FIG. 1 shows separate links 106, 107 coupling theaccess node 110 to the communication gateway 102 and the controller node104, respectively, in some cases a single physical link may connect theaccess node 110 to the core network, and communication may bedistributed to the various components of the core network by routers orother network equipment. In the context of 4G LTE and 5G networks, thelinks 106, 107 may be referred to as an S1 link or S1 interface and thelink 108 may be referred to as an X2 link or X2 interface. One ofordinary skill in the art would recognize that links 106, 107, and 108is not limited to any specific technology architecture, such as LTE or5G NR, and may be used with any network architecture and/or protocol.

Gateway 102 may be a network node configured to interface with othernetwork nodes using various protocols. Gateway 102 may communicate data(e.g., data related to a user) over system 100. Gateway 102 may be astandalone computing device, computing system, or network component, andmay be accessible, for example, by a wired or wireless connection, orthrough an indirect connection such as through a computer network orcommunication network. For example, gateway 102 may include a servinggateway (SGW) and/or a public data network gateway (PGW), etc. One ofordinary skill in the art would recognize that gateway 102 is notlimited to any specific technology architecture, such as LTE or 5G NR,and may be used with any network architecture and/or protocol.

Gateway 102 may include a processor and associated hardware circuitryconfigured to execute or direct the execution of computer-readableinstructions to obtain information. Gateway 102 may retrieve and executesoftware from a storage device, which may include a disk drive, a flashdrive, or a memory circuitry or device, and which may be local orremotely accessible. The software may include computer programs,firmware, or other form of machine-readable instructions, and mayinclude an operating system, utilities, drivers, network interfaces,applications, or other type of software, including combinations thereof.Gateway 102 may receive instructions and other input at a userinterface.

Controller node 104 may be a network node configured to communicateinformation and/or control information over system 100. For example,controller node 104 may be configured to transmit control informationassociated with a handover procedure. Controller node 104 may be astandalone computing device, a part of a computing system (e.g., aprogram, container, or virtual machine running on a computing system), anetwork component, or the like. The controller node 104 may beaccessible, for example, by a wired or wireless connection, or throughan indirect connection such as through a computer network orcommunication network. For example, controller node 104 may include oneor more of a mobility management entity (MME), a Home Subscriber Server(HSS), a Policy Control and Charging Rules Function (PCRF), anauthentication, authorization, and accounting (AAA) node, a rightsmanagement server (RMS), a subscriber provisioning server (SPS), apolicy server, etc. One of ordinary skill in the art would recognizethat controller node 104 is not limited to any specific technologyarchitecture, such as LTE or 5G NR, and may be used with any networkarchitecture and/or protocol.

Controller node 104 may include a processor and associated hardwarecircuitry configured to execute or direct the execution ofcomputer-readable instructions to obtain information. Controller node104 may retrieve and execute software from a storage device, which mayinclude a disk drive, a flash drive, a memory circuitry or device, andwhich may be local or remotely accessible. In an example embodiment,controller node 104 may include a database 105 configured for storinginformation related to elements within system 100, such asconfigurations and capabilities of relay nodes 120, resourcerequirements of end-user wireless devices 140, priority levelsassociated therewith, and so on. The information may be requested by orshared with access nodes 110 via communication links 106, 107, 108 andso on. The software may include computer programs, firmware, or otherform of machine-readable instructions, and may include an operatingsystem, utilities, drivers, network interfaces, applications, or othertype of software, and combinations thereof. In some examples, thecontroller node 104 is, or includes, an instance of the processing node400 described below in relation to FIG. 4 . In some embodiments,controller node 104 may receive instructions and other input at a userinterface.

Other network elements may be included in system 100 and configured tofacilitate communication but are omitted for clarity, such as basestations, base station controllers, mobile switching centers, dispatchapplication processors, and location registers such as a home locationregister or visitor location register. Furthermore, other networkelements that are omitted for clarity may be included in system 100 tofacilitate communication, such as additional processing nodes, routers,gateways, and physical and/or wireless data links for carrying dataamong the various network elements, e.g., between access node 110 andcommunication network 101.

FIGS. 2A and 2B depict an example dual connectivity node-pair 170 of thesystem 100. The node-pair 170 includes a first access node 110 aconfigured to utilize a first RAT and a second access node 110 bconfigured to utilize a second RAT. The node-pair 170 also includes acell site router (“CSR”) 175, which routes communication between thenetwork core 150 and the nodes 110 a,b, as well as communication betweenthe core network 150 and the nodes 110 a,b. Thus, the CSR 175 may form apart of the link 108 connecting the nodes 110 a,b together, as well as apart of the links 106,107 connecting the nodes 110 a,b to the corenetwork 150. More specifically, in examples in which the nodes 110 a,butilize LTE and 5G NR technologies, the CSR 175 may form a part of theX2 interface that couples the two nodes together as well as part of theS1 interface that couples the nodes 110 a,b to the core network 150.

The nodes 110 a,b are part of a dual-connectivity node-pair, and thus awireless device 140 may be able to connect to both nodes 110 a,b at thesame time. For example, the nodes 110 a,b may utilize EN-DC techniques.In one example, the first access node 110 a may act as a master node andthe second access node 110 b may act as a secondary node. Thus, in suchan example, control plane data may be communicated between first accessnode 110 a and the wireless device 140 via wireless link 145 a. Thewireless device 140 may initially connect to the master node, and themaster node may initiate a connection with the secondary node. Once thewireless device 140 is connected to both the master node and thesecondary node, there are various arrangements for how user plane datamay flow between the core network 150, the node-pair 170, and thewireless device 140. In one arrangement, user plane data may becommunicated between the master node and the wireless device 140 beforeestablishing the connection to the secondary node, but afterestablishing the connection to the secondary node, user-plane data myflow exclusively between the secondary node and the wireless device 140.In another arrangement, user plane data may flow between both nodes 110and the wireless device 140, including simultaneous communication insome examples. In examples in which both nodes 110 communicateuser-plane data, it may be necessary to split up the communication ofthe wireless device 140 into separate streams for transmission by therespective access nodes 110 a,b. In some examples, the decision ofwhether and how to split communication into multiple streams fortransmission by the respective nodes 110 a,b may be the responsibilityof one of the nodes 110 a,b. Either the master node or the secondarynode may be given this responsibility.

FIG. 2B illustrates an example arrangement in which the second accessnode 110 b, which is the secondary node, controls whether and how userplane communication are split. Thus, in this example, all user planecommunication 180 sent from the core network 150 to the CSR 175 arerouted first to the second access node 110 b, and the second access node110 b determines what to do with the communication (e.g., whether andhow to split the communication 180 into separate streams). The secondaccess node 110 b may split the communication into separate streams fortransmission to, for example, improve throughput or other metrics. FIG.2B illustrates the communication 180 being split by the second accessnode 110 b into a first data stream 181 for transmission by the secondaccess node 110 b and a second data stream 182 for transmission via thefirst access node 110 a. The second stream 182 is sent from the secondaccess node 110 b to the first access node 110 a, from whence it istransmitted to the wireless device 140. In the example illustrated inFIG. 2B, the CSR 175 communicably connects the first and second accessnodes 110 a,b, and therefore when the second access node 110 b sends thesecond data stream 182 to the first access node 110 a, this isaccomplished by sending the stream 182 to the CSR 175, which then routesthe stream 182 to the first access node 110 a. Thus, in this examplesome of the user plane data (e.g., the data that makes up stream 182)passes through the CSR 175 twice, once on its way to the second accessnode 110 b as part of communication 180 before splitting and once againon its way to the first access node 110 a as part of stream 182post-split. In addition, control plane communication may also continueto be handled by the first access node 110 a. In some examples, thecontrol plane communication may be passed by the CSR 175 directly to thefirst access node 110 a without being sent to the second access node 110b first, as illustrated by the communication 183 in FIG. 2B.

In a dual connectivity node-pair, such as the example node pair 170illustrated in FIGS. 2A and 2B, there may be a substantial amount ofdata passing through a shared network device, such as the CSR 175. Thisdata may include the usual data that would pass through an access node110 that is not configured for dual-connectivity, but may also includeadditional inter-node traffic in a dual-connectivity system. Inparticular, as explained above, some of the user-plane data may passthrough the CSR 175 twice. In view of this substantial load, some packetdrops may occur at the CSR 175. Thus, as explained above, the system 100may monitor the amount of packet drops at the CSR 175, and may inhibithandovers to the node-pair 170 if the packet drops get too high. Thefunctionality of monitoring the packet drops and inhibiting thehandovers may reside in one or both of the access nodes 110 a,b, the CSR175, the controller node 104, in some other device, or in somecombination of these. In one example, CSR 175 may report the amount ofpacket drops to one or both of the access nodes 110 a, b (periodically,or upon request), and one or both of the access nodes 110 a,b mayinclude logic for monitoring the packet drop amount and determiningwhether (and if so how much) to adjust handover parameters to inhibithandovers to the node-pair 170. The one of the access nodes 110 a,b mayalso communicate information with adjoining access nodes 110 that mayenable them to also adjust handover parameters to inhibit handovers tothe node-pair 170.

FIG. 3 depicts an example access node 310. Access node 310 may include,for example, a macro-cell access node. Access node 310 may be anembodiment of access node 110 described with reference to FIGS. 1 and 2, and thus the description of access node 110 herein is applicable toaccess node 310 and vice-versa. Access node 310 may include a processingcircuitry 311 configured to perform various operations described hereinfor dynamic handover parameter adjustment based on packet drop rate. Inaddition, processing circuitry 311 may be configured to schedule orallocate resources, including downlink and uplink resources, forwireless devices communicably coupled to the access node 310, such asrelay nodes and/or end-user wireless devices that are directly connectedwith access node 310. The processing circuitry 311 may include logic forperforming the various operations, with the logic comprising hardware,software, or any combination thereof. Access node 310 may also include,a memory 313, one or more transceivers 314, and one or more antennas315.

In some examples, the processing circuitry 311 may include a processor312 and a memory 313 storing software (instructions) executable by theprocessor 312 to cause the processor 312 to perform one or more of theoperations described herein. In examples in which the processingcircuitry 311 includes a processor 312, the processing circuitry 311 maybe considered as being configured to perform various operationsdisclosed herein by virtue of the memory 313 storing instructions toperform those operations such that they could be accessed and executedby processor 312. Thus, the processor 312 does not necessarily need tobe executing or have executed the instructions to be considered as beingconfigured to perform the operations—as long as the instructions arepresent in a state in which they could be executed upon operation of thedevice, then the processing circuitry may be considered as beingconfigured to perform the operations. The processor 312 may include anyprocessing resource capable of executing machine readable instructions,such as, for example, a processor, a processor core, a centralprocessing unit (CPU), a controller, a microcontroller, a system-on-chip(SoC), a digital signal processor (DSP), a graphics processing unit(GPU), etc.

As another example, the processing circuitry 311 may include dedicatedhardware (not illustrated), in addition to or in lieu of the processor312, to perform some or all of the operations described herein. Examplesof such dedicated hardware may include an Application SpecificIntegrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), aComplex Programmable Logic Device (CPLD), or the like. The processingcircuitry 311 may also include any combination of dedicated hardware andprocessor/software.

Transceiver(s) 314 and antenna array(s) 315 may be configured to providean air interface to enable wireless communication with wireless devices.The wireless interface provided may be provided via one or more cells,each having a corresponding frequency band, RAT, and coverage area. Theprocessing circuitry 311 may be configured to direct or control thetransceiver(s) 314 in the deployment of the wireless radio airinterface. Antenna array(s) 315 may include one or more antenna elementsthat are configured to deploy air interfaces over one or more wirelesssectors, form beams within these sectors, employmultiple-input-multiple-output (MIMO), etc. In some examples, the sameantenna array 315 may be configured to provide air interfaces fordifferent RATs. For example, one set of antennae elements may beconfigured to utilize a 4G LTE interface while another set of antennaeelements may be configured to utilize a 5G NR air interface. Thus, insome examples, one antenna array(s) 315 may be shared by multiple accessnodes 310 (e.g., an LTE eNodeB access node 310 and a 5G NR gNodeB accessnode 310), which may be collocated at the same cell site.

In FIG. 3 various components of the access node 310 are illustrated anddescribed separately for convenience of description, but this should notbe misunderstood as implying that these components are necessarilyphysically distinct. In other words, components of an access node 310that were illustrated and described separately may be embodied in thesame underlying hardware. For example, the transceiver(s) 314 may beembodied, in whole or in part, in the processing circuitry 311, such asin processor 312, or vice-versa.

In addition to the possibility of multiple access nodes 310 sharing anantenna array 315, in some examples, multiple access nodes 310 may shareother hardware, such as a power supply, networking devices (e.g., cellsite-router (CSR), and so on. Such sharing of hardware may include, insome examples, sharing processing hardware that forms the processingcircuitry 311 of the access nodes, using virtualization techniques. Forexample, the processing functions of the various access nodes 310 may beinstantiated as separate software programs, containers, virtualmachines, etc., running on the same hardware. Virtualization allowsmultiple processing systems to share the same underlying processinghardware, while still behaving (and appearing to other entries) in manyways as if they are physically separate systems. Functionally, suchaccess nodes 310 may continue to operate as logically separate anddistinct nodes, despite being instantiated on shared hardware. Systemssharing the same processing hardware by virtualization may be referredto as “logical” or “virtual” systems. Thus, in examples in which theprocessing functions of an access node 310 are instated on sharedhardware, the processor 312 may be referred to as a virtual processor312, and the access nodes 310 may be referred to as virtual access nodes310. This usage of “virtual” in no way implies that the access node 310is ephemeral, transitory, or any less “real” or substantial than anon-virtualized access node 310—the same underlying physical hardwaremay be present in both virtual and non-virtual access nodes 310—rather,the term “virtual” merely signifies that some of the underlying physicalprocessing hardware is shared. Such virtualization of access nodes 310may be beneficial, for example, in scenarios where multiple access nodes310 are to be deployed in the same cell site, as it may reduced theamount of physical equipment that needs to be located at the site. Forexample, in a dual connectivity scenario, an eNodeB and a gNodeB thatare to form a dual-connectivity pair may be deployed together in thesame physical device (“box”). Similarly, other components of the network(e.g., the CSR 175) may also be virtualized.

FIG. 4 depicts an example processing node 400, which may be configuredto perform some or all of the methods and operations disclosed hereinfor dynamic handover parameter adjustment. In some embodiments,processing node 400 may be included as part of an access node, such asaccess node 110 or 310. In other embodiments, processing node 400 may beincluded in some other device, such as controller node 104.

Processing node 400 may include a processing system 405. Processingsystem 405 may include a processor 410 and a storage 415. Storage 415may include a disk drive, a flash drive, a memory, or other storagedevice configured to store data and/or computer readable instructions orcodes (e.g., software). The computer executable instructions or codemaybe accessed and executed by processor 410 to perform variousoperations or methods disclosed herein. Software stored in storagedevice 415 may include computer programs, firmware, or other form ofmachine-readable instructions, including an operating system, utilities,drivers, network interfaces, applications, or other type of software.For example, software stored in storage device 415 may include a modulefor performing various operations described herein. Processor 410 may bea microprocessor and may include hardware circuitry and/or embeddedcodes configured to retrieve and execute software stored in storagedevice 415.

In examples in which the processing node 400 is included in the accessnode 110, 310, the processing node 400 may be an embodiment of, mayinclude, or may be included in, the processing circuitry 311.

Processing node 400 may include a communication interface 420 and a userinterface 425. Communication interface 420 may be configured to enablethe processing system 405 to communicate with other components, nodes,or devices in the wireless network. Communication interface 420 mayinclude hardware components, such as network communication ports,devices, routers, wires, antenna, transceivers, etc. User interface 425may be configured to allow a user to provide input to processing node400 and receive data or information from processing node 400. Userinterface 425 may include hardware components, such as touch screens,buttons, displays, speakers, etc. Processing node 400 may furtherinclude other components such as a power management unit, a controlinterface unit, etc.

Some examples of the disclosed techniques and methods for dynamichandover parameter adjustment are discussed further below. FIG. 5illustrates an example method for dynamic handover parameter adjustment.Method 500 may be performed by any suitable processing circuitry, suchas for example by a processor included in access node 110 or 310,processing node 400, or controller node 104. For discussion purposes, asan example, method 500 is described below as being performed by aprocessor included in access node 110, 310.

Method 500 may include monitoring an amount of packet drops at a sharednetwork device of a dual connectivity node pair (step 610). The sharednetwork device may be, for example a cell-site router such as the CSR175. In some examples, the monitored amount of packet drops may be anumber of packet drops that occurred during a designated time period(e.g., the most recent five (5) second interval). In some examples, themonitored amount of packet drops may be some statistical aggregation ofthe raw packet drop data, such as a moving average of packet drops perunit time, a peak number of packet drops per unit time during aspecified interval, etc. Data on the number of packet drops may beprovided to the monitoring entity (e.g., the access nodes 110, 310) bythe CSR 175, which may be configured to collect and report thisinformation. The CSR 175 may provide the information periodically to themonitoring agency without prompting, or the monitoring agency mayrequest the information from the CSR 175 as needed.

Method 500 may also include dynamically adjusting one or more handoverparameters based on the amount of packet drops at the shared networkdevice (step 520). In particular, the parameters may be adjusted suchthat handovers to the node-pair are inhibited when packet drop amount ishigh. In other words, the parameters are adjusted such that handoversare less likely (more difficult) when the amount of packet drops isrelatively high and more likely (less difficult) when the amount ofpacket drops is relatively low. Examples of handover parameters that maybe adjusted to inhibit handovers include handover thresholds, handoveroffsets, and the like.

In some examples, the inhibition of handovers based on packet drops maybe binary, meaning that handovers are either inhibited to a fixed degreeor not at all based on the packet drops. In this case, there may be onefixed amount of by which the handover parameter is adjusted if thepacket drops exceed a threshold, and otherwise no amount of packet-dropadjustment is applied.

In other examples, the degree to which handovers are inhibited may varybased on the degree to which packet drops are occurring. In such cases,the adjustment of the handover parameters may involve more gradations,with multiple different adjustment amounts being used depending on theamount of packet drops. The variation of the adjustment amount may be astep-wise (discrete) variation between a finite set of pre-specifiedadjustment amounts, or the adjustment amount may be a continuousfunction of the packet drop amount. One example of discrete steps ofvariation involves comparing the packet drop amount to multiplethreshold values, with each threshold being associated with a differentadjustment amount—e.g., if packet drops reach a first threshold, thenthe handover parameters may be adjusted by a first amount and if packetdrops reach a second threshold then the handover parameters may beadjusted by a second amount. One example of varying the adjustmentamount as a continuous function of the packet drop amount would be tovary the adjustment amount proportionally to (i.e., as a linear functionof) the packet drop amount. Any other functional relationship could beused, such as a logarithmic relationship, polynomial relationship,exponential relationship, etc. In some examples, functionalrelationships and discrete threshold testing may be combined. Forexample, no adjustment may be applied if packet drops are below athreshold value but if packet drops reach/exceed the threshold valuethen the parameter is adjusted with the adjustment amount varying as afunction of packet drops thereafter.

The adjustment of the handover parameter may be dynamic. This means thatthe determinations to adjust the parameter are made during normal systemusage and can vary in real-time based on feedback of a current state ofa system variable (i.e., packet drop amount). This is in contrast to astatic adjustment that may occur only during special states (e.g.,initialization, shutting down, maintenance, manual use adjustment, etc.)and/or or that does not vary in real time based on the current state ofa system variable. In this context, “in real-time” refers to respondingto changes in the system variable within a relatively short amount oftime from when the change occurs, such as within a few seconds. The“current state” of the system variable refers to a state of the systemvariable as measured/determined/reported relatively recently, such aswithin the last few seconds or within an amount of time equal to a fewmeasurement/reporting intervals of the system variable. In someexamples, the adjustment of the parameters may also involve someprovision for hysteresis, to avoid frequent oscillation between states.For example, once handover parameters have been adjusted to inhibithandovers based on the packet drops, they may be kept in their adjustedstate for a designated amount of time.

As noted above, a handover parameter may include, for example, athreshold, an offset, or the like. A handover threshold may be a valuethat is compared to a signal strength of a cell (or some other valuerelated to signal strength, such as the difference between two signalstrengths) as part of evaluating a handover criterion used to determinewhether to proceed with a handover. For example, one handover criterionmay be that a handover to a target cell may occur if the signal strengthof its current serving cell is below a threshold value TH₁ and thesignal strength of the target cell exceeds a threshold value TH₂. Insuch a case, the network could inhibit handovers to a given node-pair bydecreasing the value of TH₁ and/or increasing the value of TH₂ for thetarget cell. A handover offset may be a value that is added to orsubtracted from a signal strength of a cell for evaluating a handovercriteria. For example, one handover criterion may be that a handover toa target cell may occur if the signal strength of the target cell minusan offset O₁ for the target cell exceeds the signal strength of thecurrently serving cell plus an offset O₂ for the serving cell. In such acase, the network could inhibit handovers to a given node-pair byincreasing the value of O₁ for the given node pair and/or increasing thevalue of O₂ for the serving cell.

The handover criteria mentioned above are merely examples used forpurposes of illustration, and any handover criterion or combination ofcriteria may be used. One of ordinary skill in the art would be familiarwith many different types of handover criteria, such as those specifiedin various wireless communication protocols, standards, specifications,etc., and thus such well-known handover criteria are not described indetail herein. Some examples of handover criteria specified by acommunication protocol/standard include, but are not limited to, the A1,A2, A3, A4, A5, B1, and B2 measurement events specified for LTE and 5Gsystems.

Although thresholds and offsets are described above separately for easeof explanation, there is not necessarily a strict delineation between athreshold and an offset. The same parameter could function as an offsetwhen a handover criterion is expressed one way and as a threshold whenthe criterion is expressed in another logically equivalent way. Forexample, the criterion S₁ + P₁ > S₂ involves adding P₁ to a signalstrength measurement S₁ and comparing the result to another signalstrength measurement S₂, and in this expression of the criterionparameter P₁ is functioning as an offset (a value added to a signalstrength measurement). But this handover criteria could be equivalentlyexpressed as S₂ - S₁ < P₁, in which case the parameter P₁ is nowfunctioning as a threshold (a value to which something is compared)rather than as an offset.

There may be other handover parameters utilized in a network besidesthresholds and offsets, such as hysteresis values, coefficients orscaling factors (values that are multiplied or divided with othervalue), timing parameters, and so on. Any handover parameter may be usedfor the packet-drop adjustment as long adjusting the parameter in acertain direction inhibits handovers to the node-pair. In some examples,the handover parameter that is adjusted based on the packet drops mayalso be used for other purposes. For example, the handover parameterthat is adjusted based on the packet drops may be a handover parameterthat is defined by a wireless communication protocol, standard, orspecification, and which may have been originally intended for somepurpose other than packet-drop adjustments in a dual-connectivityscenario. In other words, the techniques disclosed herein may beintegrated into existing handover protocols without necessarily needingto define new handover parameters specific. In other examples, thehandover parameter that is adjusted may be a new parameter that isspecific to the packet-drop considerations described herein. Someexample signal levels may comprise a Received Signal Strength Indicator,(RSSI), Reference Signal Received Quality (RSRQ), RSRP, or any othersuitable signal level.

In some examples, the currently serving access nodes may controlhandovers of the wireless devices connected thereto, rather than thetarget access node directly controlling the handovers. For example, thewireless devices may perform measurements and communicate them to theirserving node, and then the serving node may apply the handover criteriausing the handover parameters to determine whether or not a handover mayproceed. In other examples, the wireless devices may participate moreactively in the handover process. For example, in addition to performingmeasurements, the wireless devices may also determine if handovercriteria are met based on handover parameters specified by the network,and may information the access node that it would like a handover. Insome cases, the serving access node will trust that the wireless devicecorrectly applied the handover criteria, which may be defined as part ofa wireless communication protocol, for example, and thus will initiatethe handover without much oversight. In such cases, the serving accessnode exercises indirect control over the handovers by setting andcommunicating the handover parameters to the wireless devices. In othercases, the access node may perform some checks or validations beforeinitiating the handover based on the wireless device’s request.Regardless of how much direct control the serving access node exerts onthe process, the serving access node usually plays some role in thehandover process for its connected wireless devices, including usuallyat least the setting of handover parameters.

Thus, in some examples, in order to inhibit handovers to a first accessnode (which may be part of an access-node-pair), a second adjoiningaccess node may need to adjust the values of its handover parameters,rather than (or in addition to) the first access node adjusting its ownhandover parameters. Thus, when a node-pair experiences high packetdrops, it may need to communicate packet-drop information with itsneighboring access nodes so that they can adjust their handoverparameters to inhibit handovers to the node-pair. The packet-dropinformation may be any information that enables the neighboring accessnodes to determine, qualitatively or quantitatively, an amount of packetdrops at the affected node pair. Qualitatively determining the amount ofpacket drops may comprise determining that an amount of packet drops ishigh or low without necessarily knowing the exact quantitative number ofpacket drops. For example, a notification/instruction received from anode-pair that the inhibiting of handovers to the node-pair is neededcan be considered as packet-drop information that qualitativelyindicates to the receiving access node that the amount of packet dropsat the node-pair is high. Quantitatively determining the amount ofpacket drops may comprise determining a number that represents theamount of packet drops, such as a packet drop rate number reported by ashared network device, a statistical aggregation of packet drop data(e.g., moving average number packet drops), or the like. In examples inwhich the packet drop information is qualitative, the receiving node mayapply a predetermined amount of adjustment to the handover parameter orrely the sender to instruct how much to adjust the handover parameterby. In some examples in which the packet drop information isquantitative, the receiving node may be able to determine a variableamount of adjustment for the handover parameter on its own.

Thus, in some examples of Method 500, the access node that adjusts itshandover parameters in Step 520 is part of the dual-connectivitynode-pair whose packet drops are monitored in Step 510, in otherexamples the access node whose handover parameters are adjusted in Step520 is not part of the dual-connectivity node pair whose packet dropsare monitored in Step 510, and in some examples both the affectedaccess-node-pair and the adjacent access node may adjust their ownhandover parameters. Moreover, when it is said herein that an entity“adjusts” a handover parameter, this may include both an access nodedirectly adjusting its own handover parameters (e.g., by sending outadjusted values for the handover parameters to its connected wirelessdevices) and an access node indirectly adjusting another node’s handoverparamters sending the other access node a message that causes (or isconfigured to cause) the second access node to directly adjust itshandover parameters.

FIG. 6 illustrates another example method for dynamic handover parameteradjustment. Method 600 may be performed by any suitable processingcircuitry, such as for example by a processor included in access node110 or 310, processing node 400, or controller node 104. For discussionpurposes, as an example, method 600 is described as being performed by aprocessor included in access node 110. Method 600 may be one specificexample implementation of step 520 of Method 500.

Method 600 includes detecting whether an amount of packet drops at ashared network device (e.g., cell site router) of a dual connectivitynode pair satisfies a threshold criterion (step 510). The thresholdcriterion may include comparing the amount of packet drops to athreshold value to determine if the amount of packet drops meets thethreshold value. The threshold criterion may be satisfied if the amountof packet drops exceeds the threshold value, or in some examples if theamount of packet drops equals-or-exceeds the threshold value.

Method 600 may also include, in response to the amount of packet dropsat the shared router satisfying the threshold criterion, inhibitinghandovers to one or more cells of the node-pair (Step 620). Theinhibiting of handovers may include adjusting a handover parameter, asdescribed above. In some examples, only one threshold value isconsidered, and only one level of adjustment amount is used foradjusting the handover parameter, as discussed above. In other examples,multiple thresholds may be considered and multiple different levels ofadjustment may be used dependent on which thresholds are met, asdiscussed above. In some examples, the inhibiting of handovers mayinclude the total prevention of all handovers to the access nodes. Thismay be accomplished by, for example, adjusting a handover parameter tosufficiently high (or low) level that handovers are practicallyimpossible, or by instituting a policy or state in which handovers arenot allowed (without necessarily adjusting any handover parameters).

FIG. 7 illustrates another example method for dynamic handover parameteradjustment. Method 700 may be performed by any suitable processingcircuitry, such as for example by a processor included in access node110 or 310, processing node 400, or controller node 104. For discussionpurposes, as an example, method 700 is described as being performed by aprocessor included in access node 110. Method 700 may be one specificexample implementation of Method 500.

Method 700 includes monitoring packet drops at a shared network device(e.g., router) of an N^(th) dual-connectivity access-node-pair (Step710). In some examples, the N^(th) access node-pair may be part of theentity that is performing Method 700 (i.e., an access node of the N^(th)access-node pair is monitoring its own shared network device). In otherexamples, the N^(th) access node-pair may be different from the entitythat is performing Method 700. For example, another access node maymonitor for high packet drops at a neighboring access node-pair. Asanother example, a device other than an access node, such as acontroller node 104, may monitor for high packet drops at a node-pair.

As noted above, the access nodes may communicate packet drop informationwith one another. The access nodes may also communication packet dropinformation with other devices, such as a controller node 104. Thispacket drop information may specify the actual quantitative amount ofpacket drops in some examples. In other examples, it may include someother indication from which the recipient can determine whether or notpacket drops are qualitatively high at the sending node-pair or whetherinhibition of handovers is needed, such as a flag that is set for ahigh-packet drop state, indicating handovers should be inhibited, andreset (i.e., not set) otherwise. Thus, in some examples, monitoring forhigh packet drops at the N^(th) access node-pair may entail monitoringfor such communication of packet drop information from the N^(th)node-pair.

Method 700 further includes determining whether there are high packetdrops at the N^(th) access node-pair, (Step 720), based on theinformation gleaned in Step 710.

In examples in which the actual quantitative amount of packet drops isobtained in Step 710, the determination in Step 720 may include applyinga threshold criterion to the amount of packet drops, as described abovein relation to step 520 of Method 500. If the threshold criterion issatisfied, then it may be determined that there is a high packet dropstate at the N^(th) node-pair, and the process may continue to step 730(YES determination result). Otherwise, the process may continue to Step740 (NO determination result).

In examples in which the packet drop information obtained in Step 710does not indicate the actual quantitative amount of packet drops, thenthe determination made in step 720 may be based on whether anycommunication has been received from the N^(th) node-pair that indicatesa qualitatively high packet drop amount. For example, if the N^(th) pairhas set a flag that indicates a high packet drop state, sent anotification of a high packet drop state, sent an instruction to inhibithandovers, sent an instruction to adjust handover parameters, or thelike, then it may be determined that there is a high packet drop amountat the N^(th) node-pair and the process may continue to step 730 (YESdetermination result). Otherwise, the process may continue to Step 740(NO determination result).

Method 700 further includes, when the determination in Step 720 isaffirmative, adjusting one or more handover parameters associated withhandovers to the N^(th) node-pair. Some handover parameters may be node-or cell-specific. Thus, for example, there may be an offset O_(n_target)that is to be used when a cell of the N^(th) node-pair is a target of ahandover determination. In other cases, handovers parameters may berelated generally to the role of cell in the handover (e.g., serving vstarget) without necessarily being cell-specific. For example, an offsetO_(target) might be applied to any cell that is being considered as atarget, including but not limited to a cell of the N^(th) node-pair. Insome examples, the handover parameter that is adjusted in Step 720 isnode- or cell-specific, such as the offset O_(n_target) noted above. Inother examples, the handover parameter that is adjusted in Step 720 isnot specific to the N^(th) node-pair, but nonetheless may be adjusted toinhibit handovers to the N^(th) node, such as the offset O_(target)noted above. In some circumstances, node- or cell-specific handoverparameters may be preferable as adjustment candidates, as this allowsinhibiting handovers to just the affected node-pair, instead ofinhibiting handovers to all adjoining cells.

In some examples, the amount by which the handover parameters are to beadjusted in Step 730 is a fixed amount that is applied wheneverinhibiting of handovers is needed. In other examples, the amount bywhich the handover parameters are adjusted in Step 730 may vary based onthe amount of packet drops. In some examples, the entity performingmethod 700 knows the actual amount of packet drops at the N^(th)node-pair and thus may determine the amount by which to adjust thehandover parameters by considering threshold criteria and/or using amapping function. In some examples, the entity performing method 700does not know the actual amount of packet drops at the N^(th) node-pair,but the packet drop information communicated from the N^(th) node-pairmay specify an amount by which the handover parameters are to beadjusted.

After adjusting the handover parameters in step 730, the process mayloop back to Step 710. This looping reflects the fact that the packetdrop state is monitored on an on-going basis, and handover parameteradjustments are made dynamically as the state of the node pair changes.Thus, the process may be repeatedly performed during normal operation ofthe network. In some examples, the process is repeated at regularintervals. In other examples, the process is repeated only when there isreason to believe that an update is needed, such as when new packet-dropinformation is communicated from the N^(th) node or when knowninformation changes (e.g., flag is changed from set to reset, or amountof packet drops changes from previous value to a new value).

Method 700 further includes, when the determination in Step 720 isnegative, removing packet-drop-related adjustments to handoverparameter(s) for N^(th) Node, if there are any (Step 740). In otherwords, if a previously detected high-packet-drop state at the N^(th)node-pair has now been resolved and packet drops have returned to anacceptable level, then any adjustments made to the handover parametersin relation to packet drops may be reverted. Other adjustments to thehandover parameters that might have also been made for other reasons arenot necessarily affected by this step. If no handover parameteradjustments for the N^(th) node-pair are in effect, then Step 740 may beomitted. The process may then loop back to step 710 for anotheriteration of the process, as noted above.

In some examples, the method 700 may be performed for each of multiplenode-pairs. For example, in a network with multiple dual-connectivitynode-pairs, an access point (or other device) may perform the method 700for each node-pair that is adjacent to it. Thus, in such examples thevalue of N may be incremented each time Step 710 is reached, with eachvalue of N corresponding to one of the access node-pairs (or to anindividual cell of a node-pair), so that a different node-pair (or adifferent cell) is evaluated each iteration of the method. When all ofthe relevant node-pairs (or cells) (e.g., all neighboring node-pairs)have been considered, N may be reset to its initial value and the methodmay be repeated as discussed above.

In the description above, it was assumed for ease of explanation thatthe packet drop amount at the shared network device is a total packetdrop amount for the entire shared network device. However, in someexamples, the packet drop amount at the shared network device could be apacket drop amount for a specific subset of the shared network device.For example, a specific port or group of ports could be of particularinterest, such as the port(s) that connect the network device to themaster access node. As another examples, the packet drop amounts may bemonitored on a per-cell basis (recall that each access node may includeone or more cells).

Furthermore, in the description above it was assumed for ease ofexplanation that when handovers are inhibited, they are inhibited forall cells of the node-pair. However, just as the packet drops could bemonitored on a more granular level (e.g., per cell), in some exampleshandovers could also be inhibited on a more granular level. For example,if traffic for a particular cell of the node-pair is experiencing highpacket drops at the shared network device, while others are not, thenhandovers to that specific cell could be inhibited while not inhibitinghandovers to other cells. Everything described above in relation toinhibiting handovers to a node-pair is applicable to inhibitinghandovers to a particular cell, and thus duplicative description thereofwill be omitted.

In some embodiments, methods 500, 600, and 700 may include additionalsteps or operations. Methods 500, 600, and 700 are not mutuallyexclusive. In example systems or devices disclosed herein, processingcircuitry (e.g., processing circuitry 311, processing system 405) may beconfigured to perform some or all of the actions or operations describedherein, including but not limited to the actions/operations of themethods 500, 600, and/or 700. In some examples, the processing circuitryis configured to perform such an action/operation by virtue of machinereadable instructions corresponding to the action/operation being storedin a non-transitory storage medium that is coupled to a processor of theprocessing circuitry such that the processor is capable of executingthose instructions during operation. Machine readable instructionscorrespond to an action/operation described herein if they are of such anature that they cause the processing circuitry to perform theaction/operation when executed by a processor of the processingcircuitry. In some examples, the processing circuitry is configured toperform an action/operation by virtue of including dedicated hardware(e.g., ASIC, FPGA, CPLD, logic circuitry) that is capable of performingthe action/operation during operation. In some examples, the processingcircuitry is configured to perform an action/operation by virtue of acombination of A) the processing circuitry including dedicated hardwareto perform some aspects of the action/operation and B) machine readableinstructions corresponding to some aspects of the action/operation beingstored in a non-transitory storage medium that is accessible to aprocessor of the processing circuitry.

The example systems and methods described herein may be performed by, orunder the control of, a processing system executing computer-readablecodes embodied on a computer-readable recording medium or communicationsignals transmitted through a transitory medium. The computer-readablerecording medium may be any data storage device that can store datareadable by a processing system, and may include both volatile andnonvolatile media, removable and non-removable media, and media readableby a database, a computer, and various other network devices.

Examples of the computer-readable recording medium include, but are notlimited to, read-only memory (ROM), random-access memory (RAM), erasableelectrically programmable ROM (EEPROM), flash memory or other memorytechnology, holographic media or other optical disc storage, magneticstorage including magnetic tape and magnetic disk, and solid statestorage devices. The computer-readable recording medium may also bedistributed over network-coupled computer systems so that thecomputer-readable code is stored and executed in a distributed fashion.The communication signals transmitted through a transitory medium mayinclude, for example, modulated signals transmitted through wired orwireless transmission paths.

The above description and associated figures teach the best mode of theinvention. The following claims specify the scope of the invention. Notethat some aspects of the best mode may not fall within the scope of theinvention as specified by the claims. Those skilled in the art willappreciate that the features described above can be combined in variousways to form multiple variations of the invention. As a result, theinvention is not limited to the specific embodiments described above,but only by the following claims and their equivalents.

What is claimed is:
 1. A method, comprising: monitoring an amount ofpacket drops at a shared cell site router of a dual connectivityaccess-node-pair; and detecting whether the amount of packet dropssatisfies a threshold criterion; and in response to the amount of packetdrops satisfying the threshold criterion, dynamically adjusting one ormore handover parameters to inhibit handovers to a cell of the dualconnectivity access-node-pair based on the amount of packet drops at theshared cell site router.
 2. The method of claim 1, wherein the adjustingthe one or more handover parameters to inhibit handovers to a cell ofthe dual connectivity access-node-pair comprises increasing ordecreasing values of the one or more handover parameters by fixedamounts.
 3. The method of claim 1, wherein the adjusting the one or morehandover parameters to inhibit handovers to a cell of the dualconnectivity access-node-pair comprises increasing or decreasing valuesof the one or more handover parameters by variable amounts, with theamounts by which the values of the one or more handover parameters areincreased or decreased being based on the amount of packet drops.
 4. Themethod of claim 3, further comprising determining the amounts by whichthe values of the one or more handover parameters are increased ordecreased by evaluating a mathematical function that maps amount ofpacket drops to amounts of adjustment for the one or more handoverparameters.
 5. The method of claim 1, wherein the dynamically adjustingthe one or more handover parameters based on the amount of packet dropsat the shared cell site router comprises: in response to the amount ofpacket drops ceasing to satisfy the threshold criterion, removing theadjustments to the one or more handover parameters.
 6. The method ofclaim 1, wherein the monitoring the amount of packet drops and thedynamically adjusting the one or more handover parameters are performedat an adjacent access node that is separate from the access-node-pair.7. The method of claim 6, wherein the monitoring the amount of packetdrops comprises monitoring for packet drop information communicated fromthe dual connectivity access-node-pair.
 8. The method of claim 7,wherein the packet drop information comprises a qualitative indicationof whether the amount of packet drops is high at the shared cell siterouter of the dual connectivity access-node-pair.
 9. The method of claim7, wherein the packet drop information comprises a quantitativeindication of the amount of packet drops.
 10. A system, comprising: anaccess node configured to deploy a radio air interface to providewireless services to one or more wireless devices, the access nodecomprising processing circuitry configured to: monitor an amount ofpacket drops at a shared cell site router of a dual connectivityaccess-node-pair; and detecting whether the amount of packet dropssatisfies a threshold criterion; and in response to the amount of packetdrops satisfying the threshold criterion, dynamically adjust one or morehandover parameters to inhibit handovers to a cell of the dualconnectivity access-node-pair based on the amount of packet drops at theshared cell site router.
 11. The system of claim 10, wherein theprocessing circuitry is configured to periodically transmit informationto the one or more wireless devices indicating values for handoverparameters including the one or more handover parameters; and whereindynamically adjusting the one or more handover parameters includestransmitting an adjusted value of the one or more handover parameters.12. The system of claim 10, further comprising: the dual connectivityaccess-node-pair, wherein the dual connectivity access-node-paircomprises a second access node configured to use a first radio accesstechnology (RAT) and a third access node configured to use a second RAT,wherein the access node is separate from the dual connectivityaccess-node-pair, and the access node is configured to monitor theamount of packet drops by monitoring for packet drop informationcommunicated from the dual connectivity access-node-pair.
 13. The systemof claim 12, wherein the shared cell site router is at a cell siteshared by the second and third access nodes.
 14. The system of claim 12,wherein the packet drop information comprises a qualitative indicationof whether the amount of packet drops is high at the shared cell siterouter of the dual connectivity access-node-pair or a quantitativeindication of the amount of packet drops.
 15. The system of claim 12,wherein the second access node is a long-term-evolution (LTE) eNodeB andthe third access node is a 5G New Radio (5G NR) gNodeB.
 16. The systemof claim 10, wherein the access node is part of the dual connectivityaccess-node-pair.
 17. The system of claim 10, wherein the processingcircuitry is configured to adjust the one or more handover parameters toinhibit handovers to a cell of the dual connectivity access-node-pair byincreasing or decreasing values of the one or more handover parametersby variable amounts, determine the amounts by which the values of theone or more handover parameters are increased or decreased based on theamount of packet drops.
 18. A processing node comprising circuitryconfigured to perform operations comprising: monitoring an amount ofpacket drops at a shared cell site router of a dual connectivityaccess-node-pair; and detecting whether the amount of packet dropssatisfies a threshold criterion; and in response to the amount of packetdrops satisfying the threshold criterion, dynamically adjusting one ormore handover parameters to inhibit handovers to a cell of the dualconnectivity access-node-pair based on the amount of packet drops at theshared cell site router.